1. Field of the Invention
The present invention relates to a region extraction apparatus, method and program for extracting a region, such as a lung lobe, from a three-dimensional medical image of a chest. In particular, the present invention relates to a region extraction apparatus, method and program for extracting a border of the region, such as a lung lobe.
2. Description of the Related Art
In a surgery of a lung cancer or the like, it is important to recognize interlobar fissures, which are present between lung lobe regions, and borders of lung segments to conserve pulmonary functions after the surgery and to maintain cardiopulmonary functions.
Conventionally, such information about interlobar fissures and borders of lung segments was displayed, for example, by directly inputting the information by a manual operation, or by obtaining interlobar fissures by manual input of each lung lobe region.
Meanwhile, as image recognition techniques progressed in recent years, segmentation became performed on various kinds of organs present in a three-dimensional medical image obtained by CT (Computed Tomography), MRI (magnetic resonance imaging) or the like.
For example, Japanese Unexamined Patent Publication No. 2008-142481 (Patent Document 1) discloses a method for automatically extracting interlobar fissures from a CT image, and segmenting lungs into lung lobe units by using the extracted interlobar fissures as boundary surfaces. Patent Document 1 also discloses a method for extracting plural subsegmental veins running between lung segments from a CT image of lungs, and segmenting lung lobes into lung segment units by using surfaces defined by the extracted plural subsegmental veins as boundary surfaces.